var THREE = require('three');

//
// STL Loader added
//
/**
 * @author aleeper / http://adamleeper.com/
 * @author mrdoob / http://mrdoob.com/
 * @author gero3 / https://github.com/gero3
 *
 * Description: A THREE loader for STL ASCII files, as created by Solidworks and other CAD programs.
 *
 * Supports both binary and ASCII encoded files, with automatic detection of type.
 *
 * Limitations:
 *  Binary decoding supports "Magics" color format (http://en.wikipedia.org/wiki/STL_(file_format)#Color_in_binary_STL).
 *  There is perhaps some question as to how valid it is to always assume little-endian-ness.
 *  ASCII decoding assumes file is UTF-8. Seems to work for the examples...
 *
 * Usage:
 *  var loader = new THREE.STLLoader();
 *  loader.load( './models/stl/slotted_disk.stl', function ( geometry ) {
 *    scene.add( new THREE.Mesh( geometry ) );
 *  });
 *
 * For binary STLs geometry might contain colors for vertices. To use it:
 *  // use the same code to load STL as above
 *  if (geometry.hasColors) {
 *    material = new THREE.MeshPhongMaterial({ opacity: geometry.alpha, vertexColors: THREE.VertexColors });
 *  } else { .... }
 *  var mesh = new THREE.Mesh( geometry, material );
 */

THREE.STLLoader = function(manager) {
  this.manager = manager !== undefined ? manager : THREE.DefaultLoadingManager;
};

THREE.STLLoader.prototype = {
  constructor: THREE.STLLoader,

  loadFromUrl: function(url, onLoad, onProgress, onError) {
    var scope = this;

    var loader = new THREE.XHRLoader(scope.manager);
    loader.setCrossOrigin(this.crossOrigin);
    loader.setResponseType('arraybuffer');
    loader.load(
      url,
      function(text) {
        onLoad(scope.parse(text));
      },
      onProgress,
      onError
    );
  },

  loadFromFile: function(buffer, onLoad) {
    var scope = this;
    onLoad(scope.parse(buffer));
  },

  parse: function(data) {
    var isBinary = function() {
      var expect, face_size, n_faces, reader;
      reader = new DataView(binData);
      face_size = (32 / 8) * 3 + (32 / 8) * 3 * 3 + 16 / 8;
      n_faces = reader.getUint32(80, true);
      expect = 80 + 32 / 8 + n_faces * face_size;

      if (expect === reader.byteLength) {
        return true;
      }

      // some binary files will have different size from expected,
      // checking characters higher than ASCII to confirm is binary
      var fileLength = reader.byteLength;
      for (var index = 0; index < fileLength; index++) {
        if (reader.getUint8(index, false) > 127) {
          return true;
        }
      }

      return false;
    };

    var binData = this.ensureBinary(data);

    return isBinary()
      ? this.parseBinary(binData)
      : this.parseASCII(this.ensureString(data));
  },

  parseBinary: function(data) {
    var reader = new DataView(data);
    var faces = reader.getUint32(80, true);

    var r,
      g,
      b,
      hasColors = false,
      colors;
    var defaultR, defaultG, defaultB, alpha;

    // process STL header
    // check for default color in header ("COLOR=rgba" sequence).

    for (var index = 0; index < 80 - 10; index++) {
      if (
        reader.getUint32(index, false) == 0x434f4c4f /*COLO*/ &&
        reader.getUint8(index + 4) == 0x52 /*'R'*/ &&
        reader.getUint8(index + 5) == 0x3d /*'='*/
      ) {
        hasColors = true;
        colors = new Float32Array(faces * 3 * 3);

        defaultR = reader.getUint8(index + 6) / 255;
        defaultG = reader.getUint8(index + 7) / 255;
        defaultB = reader.getUint8(index + 8) / 255;
        alpha = reader.getUint8(index + 9) / 255;
      }
    }

    var dataOffset = 84;
    var faceLength = 12 * 4 + 2;

    var offset = 0;

    var geometry = new THREE.BufferGeometry();

    var vertices = new Float32Array(faces * 3 * 3);
    var normals = new Float32Array(faces * 3 * 3);

    for (var face = 0; face < faces; face++) {
      var start = dataOffset + face * faceLength;
      var normalX = reader.getFloat32(start, true);
      var normalY = reader.getFloat32(start + 4, true);
      var normalZ = reader.getFloat32(start + 8, true);

      if (hasColors) {
        var packedColor = reader.getUint16(start + 48, true);

        if ((packedColor & 0x8000) === 0) {
          // facet has its own unique color

          r = (packedColor & 0x1f) / 31;
          g = ((packedColor >> 5) & 0x1f) / 31;
          b = ((packedColor >> 10) & 0x1f) / 31;
        } else {
          r = defaultR;
          g = defaultG;
          b = defaultB;
        }
      }

      for (var i = 1; i <= 3; i++) {
        var vertexstart = start + i * 12;

        vertices[offset] = reader.getFloat32(vertexstart, true);
        vertices[offset + 1] = reader.getFloat32(vertexstart + 4, true);
        vertices[offset + 2] = reader.getFloat32(vertexstart + 8, true);

        normals[offset] = normalX;
        normals[offset + 1] = normalY;
        normals[offset + 2] = normalZ;

        if (hasColors) {
          colors[offset] = r;
          colors[offset + 1] = g;
          colors[offset + 2] = b;
        }

        offset += 3;
      }
    }

    geometry.addAttribute('position', new THREE.BufferAttribute(vertices, 3));
    geometry.addAttribute('normal', new THREE.BufferAttribute(normals, 3));

    if (hasColors) {
      geometry.addAttribute('color', new THREE.BufferAttribute(colors, 3));
      geometry.hasColors = true;
      geometry.alpha = alpha;
    }

    return geometry;
  },

  parseASCII: function(data) {
    var geometry,
      length,
      normal,
      patternFace,
      patternNormal,
      patternVertex,
      result,
      text;
    geometry = new THREE.Geometry();
    patternFace = /facet([\s\S]*?)endfacet/g;

    while ((result = patternFace.exec(data)) !== null) {
      text = result[0];
      patternNormal = /normal[\s]+([\-+]?[0-9]+\.?[0-9]*([eE][\-+]?[0-9]+)?)+[\s]+([\-+]?[0-9]*\.?[0-9]+([eE][\-+]?[0-9]+)?)+[\s]+([\-+]?[0-9]*\.?[0-9]+([eE][\-+]?[0-9]+)?)+/g;

      while ((result = patternNormal.exec(text)) !== null) {
        normal = new THREE.Vector3(
          parseFloat(result[1]),
          parseFloat(result[3]),
          parseFloat(result[5])
        );
      }

      patternVertex = /vertex[\s]+([\-+]?[0-9]+\.?[0-9]*([eE][\-+]?[0-9]+)?)+[\s]+([\-+]?[0-9]*\.?[0-9]+([eE][\-+]?[0-9]+)?)+[\s]+([\-+]?[0-9]*\.?[0-9]+([eE][\-+]?[0-9]+)?)+/g;

      while ((result = patternVertex.exec(text)) !== null) {
        geometry.vertices.push(
          new THREE.Vector3(
            parseFloat(result[1]),
            parseFloat(result[3]),
            parseFloat(result[5])
          )
        );
      }

      length = geometry.vertices.length;

      geometry.faces.push(
        new THREE.Face3(length - 3, length - 2, length - 1, normal)
      );
    }

    geometry.computeBoundingBox();
    geometry.computeBoundingSphere();

    return geometry;
  },

  ensureString: function(buf) {
    if (typeof buf !== 'string') {
      var array_buffer = new Uint8Array(buf);
      var str = '';
      for (var i = 0; i < buf.byteLength; i++) {
        str += String.fromCharCode(array_buffer[i]); // implicitly assumes little-endian
      }
      return str;
    } else {
      return buf;
    }
  },

  ensureBinary: function(buf) {
    if (typeof buf === 'string') {
      var array_buffer = new Uint8Array(buf.length);
      for (var i = 0; i < buf.length; i++) {
        array_buffer[i] = buf.charCodeAt(i) & 0xff; // implicitly assumes little-endian
      }
      return array_buffer.buffer || array_buffer;
    } else {
      return buf;
    }
  }
};

if (typeof DataView === 'undefined') {
  DataView = function(buffer, byteOffset, byteLength) {
    this.buffer = buffer;
    this.byteOffset = byteOffset || 0;
    this.byteLength = byteLength || buffer.byteLength || buffer.length;
    this._isString = typeof buffer === 'string';
  };

  DataView.prototype = {
    _getCharCodes: function(buffer, start, length) {
      start = start || 0;
      length = length || buffer.length;
      var end = start + length;
      var codes = [];
      for (var i = start; i < end; i++) {
        codes.push(buffer.charCodeAt(i) & 0xff);
      }
      return codes;
    },

    _getBytes: function(length, byteOffset, littleEndian) {
      var result;

      // Handle the lack of endianness
      if (littleEndian === undefined) {
        littleEndian = this._littleEndian;
      }

      // Handle the lack of byteOffset
      if (byteOffset === undefined) {
        byteOffset = this.byteOffset;
      } else {
        byteOffset = this.byteOffset + byteOffset;
      }

      if (length === undefined) {
        length = this.byteLength - byteOffset;
      }

      // Error Checking
      if (typeof byteOffset !== 'number') {
        throw new TypeError('DataView byteOffset is not a number');
      }

      if (length < 0 || byteOffset + length > this.byteLength) {
        throw new Error(
          'DataView length or (byteOffset+length) value is out of bounds'
        );
      }

      if (this.isString) {
        result = this._getCharCodes(
          this.buffer,
          byteOffset,
          byteOffset + length
        );
      } else {
        result = this.buffer.slice(byteOffset, byteOffset + length);
      }

      if (!littleEndian && length > 1) {
        if (!(result instanceof Array)) {
          result = Array.prototype.slice.call(result);
        }

        result.reverse();
      }

      return result;
    },

    // Compatibility functions on a String Buffer

    getFloat64: function(byteOffset, littleEndian) {
      var b = this._getBytes(8, byteOffset, littleEndian),
        sign = 1 - 2 * (b[7] >> 7),
        exponent =
          ((((b[7] << 1) & 0xff) << 3) | (b[6] >> 4)) - ((1 << 10) - 1),
        // Binary operators such as | and << operate on 32 bit values, using + and Math.pow(2) instead
        mantissa =
          (b[6] & 0x0f) * Math.pow(2, 48) +
          b[5] * Math.pow(2, 40) +
          b[4] * Math.pow(2, 32) +
          b[3] * Math.pow(2, 24) +
          b[2] * Math.pow(2, 16) +
          b[1] * Math.pow(2, 8) +
          b[0];

      if (exponent === 1024) {
        if (mantissa !== 0) {
          return NaN;
        } else {
          return sign * Infinity;
        }
      }

      if (exponent === -1023) {
        // Denormalized
        return sign * mantissa * Math.pow(2, -1022 - 52);
      }

      return sign * (1 + mantissa * Math.pow(2, -52)) * Math.pow(2, exponent);
    },

    getFloat32: function(byteOffset, littleEndian) {
      var b = this._getBytes(4, byteOffset, littleEndian),
        sign = 1 - 2 * (b[3] >> 7),
        exponent = (((b[3] << 1) & 0xff) | (b[2] >> 7)) - 127,
        mantissa = ((b[2] & 0x7f) << 16) | (b[1] << 8) | b[0];

      if (exponent === 128) {
        if (mantissa !== 0) {
          return NaN;
        } else {
          return sign * Infinity;
        }
      }

      if (exponent === -127) {
        // Denormalized
        return sign * mantissa * Math.pow(2, -126 - 23);
      }

      return sign * (1 + mantissa * Math.pow(2, -23)) * Math.pow(2, exponent);
    },

    getInt32: function(byteOffset, littleEndian) {
      var b = this._getBytes(4, byteOffset, littleEndian);
      return (b[3] << 24) | (b[2] << 16) | (b[1] << 8) | b[0];
    },

    getUint32: function(byteOffset, littleEndian) {
      return this.getInt32(byteOffset, littleEndian) >>> 0;
    },

    getInt16: function(byteOffset, littleEndian) {
      return (this.getUint16(byteOffset, littleEndian) << 16) >> 16;
    },

    getUint16: function(byteOffset, littleEndian) {
      var b = this._getBytes(2, byteOffset, littleEndian);
      return (b[1] << 8) | b[0];
    },

    getInt8: function(byteOffset) {
      return (this.getUint8(byteOffset) << 24) >> 24;
    },

    getUint8: function(byteOffset) {
      return this._getBytes(1, byteOffset)[0];
    }
  };
}

module.exports = THREE;
